Oncolytic Virotherapy for Squamous Cell Carcinoma of the Head and Neck (HNSCC)
HNSCC is the sixth leading cancer by incidence worldwide. Treatment of locally advanced, recurrent and metastatic HNSCC is often limited by an unfavorable efficacy to toxicity ratio and median survival for patients with metastatic disease remains less than one year (Zandberg and Strome, Oral Oncology (2014) 50: 627-632). Since HNSCC is a locoregional disease that presents at or close to the surface of the body, it is amenable to initial intratumoral injection of adenoviral vectors (Ads) to prompt a loco-regional and even a systemic anti-tumor immune response (Liu et al., Nature Clinical Practice Oncology (2007) 4: 101-117). Several clinical trials of conditionally-replicating Ads (OncAds) or replication-deficient Ads encoding a therapeutic transgene have demonstrated the safety and feasibility of Ad gene therapy for HNSCC, but failed to show improved overall survival since intensive local treatment, even when combined with chemo/radiotherapy, did not prevent metastasis to distant sites (Liu et al., supra). OncAds are generally administered intratumorally, and poorly re-target to metastasized tumors (Koksi et al., Molecular Therapy: The Journal of the American Society of Gene Therapy (2015) 23:1641-1652).
OncAd with Helper-Dependent Ad (HDAd) Expressing Immunomodulatory Molecules
Adenoviral-based vectors (Ads) can infect a range of malignant cells and express high levels of lytic antigens and immunogenic transgenes, making them attractive as agents for cancer gene therapy (Cerullo et al., Advances in Cancer Research (2012) 115, 265-318). OncAds selectively replicate in cancer cells and are commonly used Ad-based vectors in clinical trials for cancer gene therapy. However, OncAds have a limited coding capacity for transgenes (˜1.5 kb). Helper-dependent Ads (HDAds) are devoid of viral coding sequences, enabling a cargo capacity of up to 34 kb for insertion of multiple transgenes in a single vector (Suzuki et al., Human Gene Therapy (2010) 21; 120-126). Since HDAd vector DNA encodes packaging signals, the OncAd replication machinery acts in trans to replicate and package both OncAd and HDAd within infected tumor cells, leading to multiple cycles of production and release of both the oncolytic virus and the transgenes encoded by the HDAd (combinatorial adenoviral vectors: CAd-VEC; Farzad et al., Molecular Therapy—Oncolytics (2014) 1, 14008).
CAR T-Cell Therapy
The use of T-cells as agents for cancer therapy has recently been facilitated by the expression of cancer cell antigen-directed chimeric antigen receptors (CARs; reviewed in Kershaw et al., Nature (2013) 13: 525-541). CAR-modified T-cells have shown promise for the treatment of hematological malignancies (Garfall et al., The New England Journal of Medicine (2015) 373:1040-1047), but have been less effective in treating solid tumors, which may in part be a consequence of the highly immunosuppressive nature of the solid tumor microenvironment (Quail et al., Nature Medicine (2013) 19:1423-1437). Due to immunosuppressive mechanisms at tumor site CAR T-cells fail to expand and persist long term despite the expression of one or two costimulatory endodomains. The present disclosure provides a solution to a long-felt need for effective cancer therapies, including combinatorial cancer therapies.